With electric motors, it is counted as belonging to the state of the art, to display different operating conditions of the motor with one or more illuminants Thus, for example, with centrifugal pumps driven by an electric motor, it is counted as belonging to the state of the art, to display the operation of the pump by way of a flashing light diode, wherein the flashing frequency can vary depending on the speed of the motor. It is regularly necessary to read the operating instructions, in which it is specified as to which light symbols correspond to which operating conditions, in order to detect the operating condition of such a motor. This is comparatively awkward since it requires the presence of the operating instructions and for the operator to look into this, which is disadvantageous.
With motors, it is counted as belonging to the state of the art, to indicate the operating condition of the running motor by way of a switched-on illuminant. However, there are also motors with which a flashing illuminant indicates the running condition of the motor. On the other hand, flashing functions of illuminants are often used to signal incorrect operating conditions, such as the standstill of the motor for example.